Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2000
Publication Date: 4/1/2000
Citation: BERRANG, M.E., NORTHCUTT, J.K., SMITH, D.P., LYON, C.E. INCIDENCE OF LISTERIA MONOCYTOGENES ON PRE-SCALD AND POST-CHILL CHICKEN CARCASSES. JOURNAL OF POULTRY SCIENCE. 2000. V. 9. P. 546-550.
Interpretive Summary: Chicken skin carries a large number of Campylobacter cells when the bird is slaughtered. These bacteria are human pathogens that have caused illness traced back to the consumption of or contact with poultry. Because skin-off chicken parts are a popular item, the question was asked: does removal of the skin lower the level of bacteria that is left on the part? Broiler breasts, thighs and drums were examined with and with-out skin at four sites within the processing plant and retail system. There were significantly less Campylobacter and other bacteria found on meat under the skin of broilers when sampled in the processing plant both before and after evisceration. Overall, parts purchased at retail had lower levels of bacteria than those sampled in the processing plant, indicating that the final steps in processing and packaging reduce bacterial contamination. However, when examined from retail outlets, there was no difference in bacterial profiles from broiler parts purchased with or without skin. Further, purchasing skin-on parts and removing the skin in the lab did not lead to lower recovery of bacteria compared to parts that had the skin left on. These results show that removal of skin from chicken parts does not affect the microbiological safety of the product.
Technical Abstract: This study was undertaken to determine if broiler chicken parts without skin are less contaminated with Campylobacter than those with skin. Samples were taken in a commercial plant from defeathered carcasses prior to evisceration and from eviscerated carcasses. Bacterial counts from rinse of aseptically removed meat samples were much lower than those from stomached skin samples. No Campylobacter were recovered from meat collected from the breast or thighs and only two of ten drum meat samples had detectable levels of Campylobacter. However, 9 of 10 breast skin, 10 of 10 thigh skin and 8 of 10 drum skin samples were positive with between log 2 and 3 CFU Campylobacter per g. Following evisceration but before entering the chill tank, there was still a significant difference in the levels of Campylobacter on breasts, thighs and drums with and without skin. While most parts without skin had detectable levels of Campylobacter, the levels were from 50 to 90% less than those with skin. Similar trends were noted for coliform, E. coli and total aerobic bacterial counts from samples collected in the plant. Broiler part samples were also collected at retail outlets. These samples were either skin-on and skinned in the lab, or skin-off at purchase. Aseptic removal of skin from broiler breasts, thighs and drums did not cause change in the levels of Campylobacter, coliform, E. coli or total aerobic counts recovered from the skinned part. Likewise, parts purchased without skin did not have different bacterial counts than paired parts purchased with the skin on. Consumers can not expect to significantly lower the number of bacteria present on a chicken breast, thigh or drum by removing the skin.